This invention relates to refrigerator units and food preparation tables where foodstuffs are kept in separate trays for use by the food preparer and served to a customer, and more particularly to an arrangement in such units for circulating cooling air to maintain a low temperature in the food trays.
In commercial fast food establishments certain foods, such as sandwiches, pizza, or salads, are prepared in volume quantities, which requires convenient access by the preparer to ingredients or condiments. These condiments are kept in separate trays for use by the food preparer for assembly into the finished foodstuff. The preparer works at a "make-up" table where the separate ingredients are combined into the finished food product. A typical food preparation table is self-contained, counter top height and formed from thermally insulated stainless steel walls into a generally oblong shaped cabinet. The cabinet includes a refrigeration unit and a chamber for storing and cooling food items. The top wall of the cabinet defines the table, is upwardly open, and has openings for receiving one or more of the foodstuff trays. The trays have their heat transferring bottom and sidewalls extending into the chamber to be cooled by a fan forcing refrigerated air around the bottom portions of the pans. The flow of air and possible loss of velocity head when cooling air must pass long distances may lead to nonuniform chamber cooling and nonuniform cooling of foodstuffs in the tray.
Existing food industry standards set by the National Sanitation Foundation ("NSF") require that a refrigeration unit simultaneously maintain the temperature of food in the tray at 45.degree. F for a prolonged period and with minimum dehydration, and the temperature in the chamber at 40.degree. F. (4.degree. C.) with a maximum of compressor run time of 70 percent in a 100.degree. F. (38.degree. C.) ambient environment, such as found in a pizza restaurant.
NSF has recently established a new and stricter standard that a refrigerated food preparation table be capable of taking a food product at 38.degree. F. and maintaining it for a period of four hours between 33.degree.-40.degree. F. (about 4.degree. C.) in a room where the ambient temperature is 100.degree. F. (about 38.degree. C.). Food preparation tables known in the prior art cannot always keep up with the product heat gain in such environment.
Further, local health codes regulating the operation of food establishments typically require that the temperature of food ingredients be maintained at about 40.degree. F. so that bacteria growth and risk of food poisoning is reduced. Perishable foodstuffs must be maintained at about 40.degree. F. to reduce food spoilage whereas ambient kitchen temperatures can exceed 85.degree. F. (29.degree. C.).
It is a principal object of this invention to provide a self-contained counter top refrigerator unit, operative as a food preparation table, wherein a controlled circulation of refrigerated air maintains both the refrigerator chamber and the condiments and/or ingredients in the separate trays extending into the chamber, at a uniform refrigerated temperature.
Another object of this invention is provision of a uniquely configured baffle plate to simultaneously direct refrigerating air at all of the condiment trays.
Another object of this invention is provision of a horizontal self-contained counter-top upwardly open food preparation table which achieves the above requirements as to control of temperature in a food pan as well as providing cooled air into the foodstuff chamber.
In accordance with this invention there is provided a refrigerated food preparation table including an oblong cabinet forming a horizontal table and having an interior cooling chamber, an arrangement for supporting condiment trays on the table such that the lower portions of the trays are positioned in the chamber, and a refrigeration system including a compressor, a condenser, an evaporator coil to refrigerate air in the cooling chamber, a row of fans to circulate air through the chamber and draw chamber air through the evaporator, and refrigerant coils for passing refrigerant through the components of the refrigeration system for connecting the refrigerator components into a refrigeration cycle.
Further, an insulated compartment is formed in the chamber adjacent to the rear wall thereof for receiving the compressor and condenser, the rear wall being proximate to the compressor for venting heated compressor air, and a partition wall of the compartment separating the evaporator from the other refrigeration equipment. The evaporator coil is supported in the cooling portion of the chamber.
A particularly constructed baffle is mounted in the cooling chamber for directing the flow of refrigerated air within the chamber and about the lower portions of the condiment trays. The baffle extends laterally between the opposite vertical sidewalls of the chamber and includes a first wall which is spaced above the compartment, a second wall which forms a first plenum above the evaporator, and a third wall which cooperates with a flange therefrom to form a second plenum adjacent to the rear wall of the cabinet, the first and third walls being generally vertically extending and the second wall being generally horizontally extending. The first wall is provided with an angled flange to define a suction inlet above the partition wall which supplies recirculated air to the evaporator. The second wall is provided with an array of openings in the form of elongated louvers which ar configured to direct air vertically from the first plenum and primarily against the bottom of the condiment trays. The third wall is provided with an array of generally square openings which are configured to direct air horizontally from the second plenum and primarily against the sidewalls of the trays and into the chamber.
Advantageously, the baffle cooperates with the evaporator and evaporator fans to provide refrigerant air in an amount sufficient to cool yet not freeze food in the condiment tray.
Further, the baffle openings substantially simultaneously provide cooling air both to all of the condiment trays and to the chamber. Proximate location of the baffle openings adjacent to the trays assure uniform heat transfer relation to the foodstuffs in the trays while other cooling air simultaneously is passed directly into the chamber for cooling the stored foodstuffs.
Further, the baffle openings are configured and positioned to direct the cooling air at a desired location such that the desired temperature of the food in the condiment pans is maintained. Efficiency of the baffle correlates into efficiency of the cooling, whereby the refrigerator unit does not have to cycle as frequently, thereby reducing operating costs.
The foregoing and other objects and advantages of this invention will become more apparent when viewed in light of the accompanying drawings and following detailed description of the invention in which: